Particle therapy installation

ABSTRACT

A particle therapy system that includes at least one irradiation chamber, in which an object is irradiated with a treatment beam, an antechamber, which is screened off from radiation occurring in the irradiation chamber and from which access is made to the irradiation chamber, and an access area, which leads to the irradiation chamber and connects the irradiation chamber to the antechamber, is provided. A support for a patient moves along a path of travel from the antechamber, through the access area, to the irradiation chamber. A radiation protection door is arranged in the access area, and the access area is configured geometrically in such a way that the path of travel in the access area is substantially rectilinear.

The present patent document is a §371 nationalization of PCT ApplicationSerial Number PCT/EP2008/060369, filed on Aug. 7, 2008, designating theUnited States, which is hereby incorporated by reference. This patentdocument also claims the benefit of DE 10 2007 042 336.7, filed Sep. 6,2007, which is also hereby incorporated by reference.

BACKGROUND

The present embodiments relate to a particle therapy system.

In particle therapy, a particle beam including protons or heavy ions(e.g., carbon ions) is created with a suitable accelerator. The particlebeam is guided in a radiation channel and exits via an exit window ofthe radiation channel into an irradiation chamber where the irradiationof a patient is undertaken. Depending on the design of the irradiationchamber, this can be done via a fixed beam exit window (e.g., fixed beamirradiation chambers) but also via a rotatable gantry to allow radiationfrom a number of angles.

The costs involved in generating and steering a particle beam aregreater by comparison with conventional radiation methods such as, forexample, with high-energy x-ray beams. In order to still be able to workefficiently, a particle therapy system usually includes a number oftreatment chambers arranged in the vicinity of one another, in each ofwhich patients can be irradiated. While an irradiation process is beingcarried out in one of the treatment chambers, patients can be preparedin the other treatment chambers for a subsequent irradiation session orcan be removed after a completed irradiation. This enables sensible useto be made of times at which no irradiation is being carried out in anirradiation chamber.

The treatment chambers are usually arranged in a particle therapy systemsuch that access to the treatment chambers is possible from a sharedcorridor and/or antechamber. Usually further chambers (e.g., therapyplanning rooms, lounges for patients or doctors, preparation chambersand/or examination chambers of patients and similar chambers), which areused in the particle therapy system, can be entered from the sharedcorridor and/or antechamber.

Since significant radiation in the form of higher-energy photonradiation, for example, can occur in an irradiation chamber because ofthe radiation treatment, the treatment chambers are constructed withradiation shielding such that other areas of the particle therapyinstallation (e.g., the corridor and/or antechamber) are not subjectedto the radiation occurring in the irradiation chamber.

This is partly made possible by thick walls, which at least partlysurround the irradiation chamber. Furthermore, solutions are known inwhich the access to the irradiation chamber is implemented by aserpentine or labyrinthine access path into which ceiling curtains canbe drawn in some cases. This prevents the irradiation occurring in theirradiation chamber from penetrating to the outside through theserpentine or labyrinthine access path. Such access to an irradiationchamber is known, for example, from WO 2004/013865 A1.

SUMMARY AND DESCRIPTION

The present embodiments may obviate one or more of the drawbacks orlimitations in the related art. For example, in one embodiment, aparticle therapy system in which a shielding of treatment chambers isimplemented in a simple, safe and low-cost way, which allows aspace-saving arrangement of the treatment chambers and makes for asimple access path to an irradiation chamber, is provided.

The particle therapy system includes: at least one irradiation chamber,in which an object is irradiated with a treatment beam; an antechamber,which is shielded from radiation occurring in a radiation chamber andfrom which there is access to the at least one irradiation chamber; andat least one access area to the at least one irradiation chamber, whichconnects the irradiation chamber to the antechamber, with aradiation-protection door being arranged in the access area

The access area is the area that makes access to the irradiation chamberpossible. In routine operation, patients are moved for irradiation viathe access area into the irradiation chamber or moved out of theirradiation chamber again after irradiation. In one embodiment, theirradiation chamber includes one access area.

In one embodiment, the geometry of the access area is configured suchthat a patient bed is able to be moved from the antechamber to theirradiation chamber along a path of travel in the access area that issubstantially rectilinear.

A serpentine or labyrinthine access path, as known from the prior art,allows an effective radiation shielding but also has disadvantages. Theserpentine or labyrinthine access path occupies a comparatively largeamount of space in a particle therapy system. Since an access path isalso formed by comparatively thick radiation protection walls, theparticle therapy system becomes larger, and higher costs arise whenbuilding the particle therapy system. A serpentine or labyrinthineaccess path, which is usually several meters in length, also causesdifficulties in handling a patient bed with a patient when the patientis being moved from the antechamber into the irradiation chamber or viceversa.

In one embodiment, a radiation protection door is arranged in the accessarea. The radiation protection door consequently ensures that, even witha simple geometry of the access area, radiation cannot escape from theradiation chamber to other chambers of the particle therapyinstallation. The radiation protection door dispenses with serpentinewinding paths, one of the purposes of which is to provide radiationshielding. The costs arising for the radiation protection door are savedby the space saved by the simpler construction of the particle therapysystem. The radiation protection door shields against a radiation, whichfor access areas with simple geometry, would otherwise penetrate moreand more into the antechamber.

In one embodiment, the radiation protection door is configured such thatthe radiation arising in the irradiation chamber, which penetratesthrough the radiation protection door, is attenuated at least by afactor of 50. In other embodiments, the radiation arising in theirradiation is attenuated by at least a factor of 75 or at least afactor of 100, respectively. In this way, the antechamber issufficiently protected against radiation (e.g., against fast neutronsand thermal neutrons arising during irradiation) even if irradiation isbeing carried out with carbon ions in the irradiation chamber, and ahigh radiation load arises by comparison with protons.

In one embodiment, the radiation protection door is made from steel. Inone embodiment, steel with a thickness of approximately 45 cm is usedfor shielding from the radiation arising during a particle therapy.However, other materials may also be used. In one embodiment, theradiation protection door may have a thickness of at least 50 cm. Inother embodiments, the radiation protection door may have a thickness ofat least 75 cm or at least 100 cm, respectively.

In one embodiment, the geometry of the access area is configured in sucha way that the path of travel in the access area is substantiallyrectilinear. Substantially rectilinear may be defined as a path in theaccess area that is configured such that a patient bed, when being movedalong the path in the access area, makes insignificant turns (e.g., lessthan 40°, 30°, or 20°) or does not make any turns at all. Further turnsare made, if at all, during the transition from the antechamber to theaccess area or from the access area to the irradiation chamber.

In one embodiment, the access area is configured such that after theradiation protection door, the patient bed is turned when moved from theaccess area into the irradiation chamber (e.g., after a patient bed hasbeen moved through the radiation protection door, the patient bed isturned again, if at all, if the patient bed is moved from the accessarea into the irradiation chamber in which the actual irradiation takesplace. A serpentine or zigzag movement is avoided by the more compactconstruction described above.

In one embodiment, the access area opens out at a sharp angle into theirradiation chamber, by which a part radiation shielding of the accessarea from the irradiation chamber is produced. This allows aspace-saving construction and also simple handling of a patient bedduring transport through the access area.

In one embodiment, the path in the access area may have a length of lessthan 10 m or, in another embodiment, less than 8 m.

A particle therapy system may include further treatment rooms, each ofwhich is accessible via a corresponding further access area from theantechamber. Each of the access areas may be configured in accordancewith the designs described above, with a radiation protection door and arectilinear access path. Both radiation protection and low productioncosts as a result of a space-saving construction and simple handling ofa patient bed to access each of the treatment rooms and access areasconfigured as described above may be provided.

In one embodiment, the access area to the irradiation chamber isarranged spatially so that a patient bed has to make a turn when beingtransferred from the access area to the irradiation chamber. Lessradiation reaches the access area from the irradiation area in theirradiation chamber, allowing the radiation protection door arranged inthe access area to be configured in a simpler and lower-cost manner.

In one embodiment, a radiation-protection wall is arranged between theirradiation chamber and the access area, by which the radiationprotection door is protected against direct radiation, which goes outfrom an irradiation center in the irradiation chamber. Theradiation-protection wall also enables the dimensions of the radiationprotection door to be narrower, since a part of the radiation isshielded off by the radiation-protection wall.

In one embodiment, the irradiation chamber includes a wall projectionsuch that a niche is formed in which neutrons generated and emitted bythe irradiation are captured.

In one embodiment, the radiation protection door may be embodied as asliding door, which allows simple handling and rapid opening or closingof the radiation protection door.

In one embodiment, the antechamber is a corridor configured such thatdirect access from the antechamber to further rooms and/or corridors ofthe particle therapy system is possible. For example, further treatmentrooms may each be accessible from the antechamber via an access area.Other rooms of the particle therapy system, such as therapy planningrooms, lounges for patients for doctors, preparation rooms and/orexamination rooms for patients or further passageways of the particletherapy system, may also be accessible from the antechamber in a directmanner.

In one embodiment, the antechamber is not a single room enclosed bywalls. The antechamber may, for example, be connected to otherpassageways/rooms of a particle therapy system without a dividing door.In one embodiment of the particle therapy system, the antechamber may bedivided up into a number of smaller rooms or corridors.

For additional radiation protection, the access area may be divided fromthe antechamber by an additional door, which is thinner than theradiation protection door. The additional door may, for example, be apolyethylene door (a PE door), which may include boron. The PE doorprovides effective shielding from thermal neutrons, which might still bepresent. Effective shielding from the fast neutrons may be provided bythe radiation protection door.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a particle therapy system known fromthe prior art,

FIG. 2 shows a schematic view of one embodiment of an irradiationchamber with an access area that has a rectilinear access path.

DETAILED DESCRIPTION

FIG. 1 shows a schematic view of the structure of a particle therapysystem 10, as is known from the prior art. In the particle therapysystem 10, a body (e.g., tumorous tissue in the body) is irradiated witha particle beam.

Ions such as, for example, protons, pions, helium ions, carbon ions orother sorts of ions, are used as particles. The particles are created ina particle source 11. If, as shown in FIG. 1, two particle sources 11,which generate two different types of ions, are provided, a switchovermay be made within a very short time between the two different types ofions. A switching magnet 12, which is arranged between the ion source 11and a pre-accelerator 13, may be used for the switchover. This allowsthe particle therapy system 10 to be operated with protons and withcarbon ions at the same time, for example.

The particles generated by the particle source 11, or by one of theparticle sources 11 and selected by the switching magnet 12 areaccelerated in a pre-accelerator 13 up to a first energy level. Thepre-accelerator 13 is a linear accelerator, for example. Subsequently,the particles are fed into an accelerator 15, for example, a synchrotronor cyclotron. In the accelerator 15, the particles are accelerated tohigh energies for irradiation. After the particles have left theaccelerator 15, a high-energy beam transport system 17 conducts theparticles to one or more irradiation chambers 19. In an irradiationchamber 19, the accelerated particles are directed onto a body to beirradiated. The accelerated particles are directed onto a body to beirradiated from a fixed direction (e.g., in fixed beam chambers) or fromdifferent directions via a gantry 21, which permits rotational movementaround an axis 22.

A total of three treatment rooms 19 are shown in FIG. 1. The treatmentrooms 19 are reached from a shared antechamber 31 (e.g., a corridor).The treatment chambers 19 are each accessed via an access area 33. Apatient bed, which is moved from the shared antechamber 31 to one of thetreatment chambers 19, is moved along a winding or serpentine path(e.g., shown in FIG. 1 as a dashed line) in the access area 33. Afterthe patient bed has been moved along the serpentine path, the patientbed reaches the irradiation chamber 19. The treatment chambers 19 aresurrounded by radiation protection walls, sometimes meters thick, sothat no or little radiation penetrates from the treatment chambers 19into the shared antechamber 31. As a result of the serpentine path inthe access areas 33, no radiation escapes to the outside via the accessareas 33. The access areas 33, therefore, occupy a great deal of space,which is surrounded by radiation protection walls, giving rise tocomparatively high costs.

FIG. 2 shows one embodiment of an irradiation chamber 19. Oneirradiation chamber 19 with surrounding structures is shown in greaterdetail in FIG. 2. A particle therapy system with such an irradiationchamber 19 may otherwise be constructed in a similar manner to theparticle therapy system shown in FIG. 1.

The irradiation chamber 19, in which a patient is to be treated, issurrounded by radiation protection walls 35. Irradiation facilities arepositioned within the irradiation chamber 19. In one embodiment, theirradiation facilities are positioned using a positioning apparatus(e.g., a robot arm 49). A patient lying on a patient bed 37 ispositioned in a desired position by the robot arm 49 in accordance witha treatment plan in relation to a beam exit channel 47. A treatment beam(e.g., indicated as a dashed line in FIG. 1) is taken from thehigh-energy beam transport system 17 to the beam exit channel 47, exitsfrom the beam exit channel 47 and hits an object to be irradiated.

With the irradiation chamber 19 shown in FIG. 2, entry from anantechamber 31 is also via an access area 33.

In one embodiment, a path 39, along which a patient bed is moved in theaccess area 33, is approximately configured as a rectilinear path. Thepath 39 is shown as a dashed line in FIG. 2. The patient bed is turnedin the threshold area between the access area 33 and the irradiationchamber 19. So that no radiation gets out into the antechamber 31 fromthe irradiation chamber 19 via the access area 33 despite the simplegeometry, a radiation protection door 51 is arranged in the access area33. Movement in the access area 33 may be such that the irradiationchamber 19 and for the most part, also the access area 33, may beradiation-shielded from the other rooms of the particle therapy system(e.g., the antechamber 31). During the irradiation process, theantechamber 31 and other rooms of the particle therapy system 10 areprotected from radiation arising in the radiation chamber 19. In oneembodiment, the radiation protection door 51 has a thickness of 1 m,with a width of 2 m.

As a result of the radiation protection door 51, the access area 33 maybe configured with a simple geometry so that a path running with anapproximately rectilinear course is provided in the access area. Thepath may also be significantly shorter compared to serpentine orlabyrinthine access areas.

In one embodiment, a further door 53 may be arranged between theantechamber 31 and the entry into the access area 33. Thus, the accessarea 33 may also be closed off without the comparatively large and heavyradiation protection door 51 having to be moved. In addition, thefurther door may shield against thermal neutrons as well.

A further radiation shielding wall 41 is arranged between theirradiation chamber 19 and the access area 33 so that radiation arisingin an irradiation center 55 cannot strike the radiation protection door51 directly. The radiation-protection wall 41 simultaneously forms aniche in which the radiation protection door 51 may be positioned if theaccess area 33 is to be opened. In one embodiment, the radiationprotection door 51 is a sliding door. The radiation-protection wall 41also forms a part of the boundary of the passageway of the access area33.

The irradiation chamber 19 also includes a wall projection 43, throughwhich a niche 45 is formed. The niche 45 is used to capture neutrons,which arise during the irradiation and are scattered at an angle (e.g.,60°) to the beam axis, and to prevent the neutrons from hitting otherobjects or reaching the outside.

While the present invention has been described above by reference tovarious embodiments, it should be understood that many changes andmodifications can be made to the described embodiments. It is thereforeintended that the foregoing description be regarded as illustrativerather than limiting, and that it be understood that all equivalentsand/or combinations of embodiments are intended to be included in thisdescription.

1. A particle therapy system, comprising: an irradiation chamber, inwhich an object is irradiated with a treatment beam; an antechamber,which is shielded from radiation occurring in the irradiation chamber;and an access area to the irradiation chamber, which connects theirradiation chamber to the antechamber so that access from theantechamber to the irradiation chamber is via the access area, wherein aradiation protection door is arranged in the access area.
 2. Theparticle therapy system as claimed in claim 1, wherein the access areais arranged spatially in relation to the irradiation chamber such thatthe access area opens out at an acute angle into the irradiationchamber.
 3. The particle therapy system as claimed in claim 1, whereinthe access area is configured such that a path along which a patient bedis moved from the antechamber to the irradiation chamber is rectilinear.4. The particle therapy system as claimed in claim 1, further comprisinga radiation-protection wall arranged between the irradiation chamber andthe access area that protects the radiation protection door from directradiation, which goes out from an irradiation center in the irradiationchamber.
 5. The particle therapy system as claimed in claim 1, wherein awall projection is arranged in the irradiation chamber such that thewall projection forms a niche in which neutrons generated and emittedduring irradiation are captured.
 6. The particle therapy system asclaimed in claim 1, wherein the radiation protection door attenuates theradiation occurring in the irradiation chamber and penetrating theradiation protection door by at least a factor of
 50. 7. The particletherapy system as claimed in claim 1, wherein the radiation protectiondoor has a thickness of at least 50 cm.
 8. The particle therapy systemas claimed in claim 1, wherein the radiation protection door is asliding door.
 9. The particle therapy system as claimed in claim 1,wherein the access area is separated from the antechamber by anadditional door, which is thinner than the radiation protection door.10. The particle therapy system as claimed in claim 1, wherein theantechamber is configured such that direct access is possible from theantechamber to further rooms, further corridors, or both further roomsand further corridors of the particle therapy system.
 11. The particletherapy system as claimed in claim 2, wherein the access area isconfigured such that a path along which a patient bed is moved from theantechamber to the irradiation chamber is rectilinear.
 12. The particletherapy system as claimed in claim 2, further comprising aradiation-protection wall arranged between the irradiation chamber andthe access area that protects the radiation protection door from directradiation, which goes out from an irradiation center in the irradiationchamber.
 13. The particle therapy system as claimed in claim 3, furthercomprising a radiation-protection wall arranged between the irradiationchamber and the access area that protects the radiation protection doorfrom direct radiation, which goes out from an irradiation center in theirradiation chamber.
 14. The particle therapy system as claimed in claim2, further comprising a wall projection arranged in the irradiationchamber such that the wall projection forms a niche in which neutronsgenerated and emitted during irradiation are captured.
 15. The particletherapy system as claimed in claim 4, further comprising a wallprojection arranged in the irradiation chamber such that the wallprojection forms a niche in which neutrons generated and emitted duringirradiation are captured.
 16. The particle therapy system as claimed inclaim 4, wherein the radiation protection door attenuates the radiationoccurring in the irradiation chamber and penetrating the radiationprotection door by at least a factor of
 50. 17. The particle therapysystem as claimed in claim 4, wherein the radiation protection door is asliding door.
 18. The particle therapy system as claimed in claim 6,wherein the radiation protection door is a sliding door.
 19. Theparticle therapy system as claimed in claim 7, wherein the access areais separated from the antechamber by an additional door, which isthinner than the radiation protection door.
 20. The particle therapysystem as claimed in claim 5, wherein the antechamber is configured suchthat direct access is possible from the antechamber to further rooms,further corridors, or both further rooms and further corridors of theparticle therapy system.